Bump @openzeppelin/contracts from 4.0.0-beta.0 to 4.0.0-beta.1 in /ex…

…amples/truffle (#473)

Bumps [@openzeppelin/contracts](https://github.com/OpenZeppelin/openzeppelin-contracts) from 4.0.0-beta.0 to 4.0.0-beta.1.
<details>
<summary>Commits</summary>
<ul>
<li><a href="https://github.com/OpenZeppelin/openzeppelin-contracts/commit/954f6110d6e66d0c020aa5721dc49b07eb576d06"><code>954f611</code></a> 4.0.0-beta.1</li>
<li><a href="https://github.com/OpenZeppelin/openzeppelin-contracts/commit/4390b8df123afa31ef63fa7cdca6030ff4c1a470"><code>4390b8d</code></a> Add ERC721URIStorage extension (<a href="https://github-redirect.dependabot.com/OpenZeppelin/openzeppelin-contracts/issues/2555">#2555</a>)</li>
<li><a href="https://github.com/OpenZeppelin/openzeppelin-contracts/commit/cb88e15b333f40f3fe19bb3b5662f5f1c9d2b7e4"><code>cb88e15</code></a> Enable optimizations when publishing package (<a href="https://github-redirect.dependabot.com/OpenZeppelin/openzeppelin-contracts/issues/2557">#2557</a>)</li>
<li><a href="https://github.com/OpenZeppelin/openzeppelin-contracts/commit/136de910493370472d4ab41e79261214b018f8a1"><code>136de91</code></a> Rename variable master to implementation <a href="https://github-redirect.dependabot.com/OpenZeppelin/openzeppelin-contracts/issues/2">#2</a> (<a href="https://github-redirect.dependabot.com/OpenZeppelin/openzeppelin-contracts/issues/2553">#2553</a>)</li>
<li><a href="https://github.com/OpenZeppelin/openzeppelin-contracts/commit/e2bf45f2622f1482e974ac54db57cca98407547a"><code>e2bf45f</code></a> Rename variable master to implementation</li>
<li><a href="https://github.com/OpenZeppelin/openzeppelin-contracts/commit/93d990c6530ba1038854490caf7b80c24391229e"><code>93d990c</code></a> Optimize constructor of ERC777 (<a href="https://github-redirect.dependabot.com/OpenZeppelin/openzeppelin-contracts/issues/2551">#2551</a>)</li>
<li><a href="https://github.com/OpenZeppelin/openzeppelin-contracts/commit/3dfd02b4b4550d31401e972a31dbd99b273d91c3"><code>3dfd02b</code></a> Fix link to TimelockController</li>
<li><a href="https://github.com/OpenZeppelin/openzeppelin-contracts/commit/7a7bd8f6d7784a825ecb7cbf79be114acbcb053a"><code>7a7bd8f</code></a> Fix typo Controler -&gt; Controller</li>
<li><a href="https://github.com/OpenZeppelin/openzeppelin-contracts/commit/16312fcfb9b4e7bcfa3235b8aac770521a91376c"><code>16312fc</code></a> Rename UpgradeableProxy to ERC1967Proxy (<a href="https://github-redirect.dependabot.com/OpenZeppelin/openzeppelin-contracts/issues/2547">#2547</a>)</li>
<li><a href="https://github.com/OpenZeppelin/openzeppelin-contracts/commit/a81a88cca0ef9e86cb613077381df19d1ba5f135"><code>a81a88c</code></a> Fix mentions of buidler (<a href="https://github-redirect.dependabot.com/OpenZeppelin/openzeppelin-contracts/issues/2548">#2548</a>)</li>
<li>Additional commits viewable in <a href="https://github.com/OpenZeppelin/openzeppelin-contracts/compare/v4.0.0-beta.0...v4.0.0-beta.1">compare view</a></li>
</ul>
</details>
<br />


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</details>

examples/truffle/package.json

@@ -23,7 +23,7 @@
   "homepage": "https://github.com/gnosis/ethcontract-rs",
   "devDependencies": {
     "@gnosis.pm/util-contracts": "^3.0.1",
-    "@openzeppelin/contracts": "4.0.0-beta.0",
+    "@openzeppelin/contracts": "4.0.0-beta.1",
     "@truffle/hdwallet-provider": "^1.2.2",
     "truffle": "^5.2.2",
     "truffle-plugin-verify": "^0.5.6"

examples/truffle/yarn.lock

@@ -1062,10 +1062,10 @@
     "@nodelib/fs.scandir" "2.1.4"
     fastq "^1.6.0"
 
-"@openzeppelin/[email protected].0":
-  version "4.0.0-beta.0"
-  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-4.0.0-beta.0.tgz#e16c9f5f667b05e5bf86ecbf32ed92f145a7c890"
-  integrity sha512-O/LC1F04y6PiXuU6oDRmNUIlVwoEC9mS8Lmij6nRt4N1em0fLvirK33QiDc5IgheRZQ7QJ3pyPNCRhNiZNKfLQ==
+"@openzeppelin/[email protected].1":
+  version "4.0.0-beta.1"
+  resolved "https://registry.yarnpkg.com/@openzeppelin/contracts/-/contracts-4.0.0-beta.1.tgz#23476cf3e4e3fdd9deb246457e7edea4aebe7228"
+  integrity sha512-O+zuP2DbZPHlX/ViTmewpVU12k7vi4YU6fzWRXDKzJql7RHF5mFOL/z3cILp4iVoz8wH+drFYXnQMaj8/Sc0BQ==
 
 "@protobufjs/aspromise@^1.1.1", "@protobufjs/aspromise@^1.1.2":
   version "1.1.2"